Apparatus and method for determining the optical power passing through an optical fiber

Patent · Sun Jan 01 00:00:00 EST 1995

OSTI ID:875168

Toeppen, John S. ^[1]

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1. Livermore, CA

An apparatus and method for determining the optical power transmitted through an optical fiber. The invention is based on measuring the intensity of the fluorescence produced by a doped segment of an optical fiber. The dopant is selected so that it emits light at a different wavelength than that responsible for producing the fluorescence. The doped segment is of sufficient length and dopant concentration to provide a detectable signal, but short enough to prevent the doped segment from serving as a gain medium, resulting in amplified spontaneous emission and excess fluorescence traveling along the optical fiber. The dopant material is excited by the optical signal carried by the fiber, causing a fluorescence. In the preferred embodiment the intensity of the fluorescence is proportional to the intensity of the propagating light. The signal power is then determined from the intensity of the fluorescence. The intensity of the fluorescent signal is measured by a photodetector placed so as to detect the light emitted through the side of the doped segment. The detector may wrap around the circumference of the fiber, or be placed to one side and used in conjunction with a reflector placed on the opposing side of the fiber. Filters may be used to shield the detector from other light sources and assist with accurately determining the optical power of the signal propagating within the fiber.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-48
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): H001426
• Application Number: 07/967493
• OSTI ID: 875168
• Resource Relation: Patent File Date: 1992 Oct 28
• Country of Publication: United States
• Language: English

Related Subjects

apparatus
method
determining
optical
power
passing
fiber
transmitted
based
measuring
intensity
fluorescence
produced
doped
segment
dopant
selected
emits
light
wavelength
responsible
producing
sufficient
length
concentration
provide
detectable
signal
prevent
serving
medium
resulting
amplified
spontaneous
emission
excess
traveling
material
excited
carried
causing
preferred
embodiment
proportional
propagating
determined
fluorescent
measured
photodetector
placed
detect
emitted
detector
wrap
circumference
conjunction
reflector
opposing
filters
shield
sources
assist
accurately
emits light
sufficient length
light source
preferred embodiment
optical fiber
light sources
optical signal
light emitted
optical power
accurately determining
power transmitted
spontaneous emission
statutory invention registration
/374/250/385/